Can anyone help with my Geometry?

Question

1. Find the Lateral Area of a cylinder with diameter of 12 cm and a height of 20 cm.

2. Find the Volume of a cylinder with a radius 11 cm and a height of 7 cm.

3. Find the Volume of a cone with diameter of 8 cm and a height of 12 cm.

4. Find the Surface Area of a sphere with diameter of 15 cm.

5. Find the Surface Area of a cone with a diameter of 10 cm and a height of 12 cm. Use pi = 3.14. Show your work for credit.

6. Find the Volume of a hemisphere with a diameter of 17 cm. Use pi = 3.14 and round to the nearest hundredth. Show your work for credit.

Answer 1

1.)
Lateral Surface Area
S = 2 Pi * r * h

r = (12/2) = 6

S = 2 * pi * 6 * 20
S = 240pi or about 754cm^2

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2.)
V = Pi r^2h

V = pi * 11^2 * 7
V = pi * 121 * 7
V = 847pi or about 2661cm^3

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3.)
V = Pi r^2h/3

r = (8/2) = 4

V = pi * 4^2 * 12/3
V = pi * 16 * 4
V = 64pi or about 201cm^3

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4.)
S = pi * d^2

S = pi * 15^2
S = 225pi or about 707cm^2

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5.) If you are talking about Total Surface Area and not Lateral Surface Area, then

T = Pi r(r + s)

r = 10/2 = 5

s = sqrt[r^2 + h^2]
s = sqrt(5^2 + 12^2)
s = sqrt(25 + 144)
s = sqrt(169)
s = 13

T = 3.14 * 5(5 + 13)
T = 3.14 * 5(18)
T = 282.6cm^2

But if you are talking about lateral area, then

S = Pi r*s
S = 3.14 * 13 * 5
S = 204.1cm^2

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6.) for this to be a hemisphere, h = r1, so
V = (Pi/6)(3r^2 + r^2)r
V = (pi/6)(4r^2

r= 17/2

V = (pi/6)(4(17/2)^2)(17/2)
V = (4pi/6) (17/2)^3
V = 1285.57cm^3

Answer 2

Y'know, some people edit slightly the homework they post on here, and I've no intention of getting credit... nor do I believe you would cite your sources.

All six of these answers could have been easily gotten by plugging them into the formulae in approximately the same amount of time it took you to post them here.

Answer 3

i absolutely refuse to do your homework for you....you'll never learn that way.

Answer 4

do your own homework, how would you learn, I pitty you.